Bi-annual US dollars 1987-06-30 18 1987-12-31 11 1988-06-30 10 1988-12-31 2 1989-06-30 16 1989-12-31 8 1990-06-30 3 1990-12-31 2 1991-06-30 34 1991-12-31 19 1992-06-30 15 1992-12-31 23 1993-06-30 6 1993-12-31 9 1994-06-30 6 1994-12-31 3 1995-06-30 6 1995-12-31 8 1996-06-30 6 1996-12-31 7 1997-06-30 10 1997-12-31 10 1998-06-30 7 1998-12-31 5 1999-06-30 3